1. Field of the Invention
The present invention relates to a vacuum vapor deposition apparatus for vacuum vapor-depositing metal such as zinc, ceramics and the like.
2. Description of the Prior Art
Heretofore, as an apparatus for carrying out vapor deposition onto both surfaces of a band to be vapor-deposited, the following vapor deposition apparatus were proposed.
A wrapping roll type vapor deposition apparatus proposed in Japanese Patent Publication No. 61-60912 (1986) is shown in FIG. 8. As shown in this figure, along a conveying route of a band 01 are provided vacuum tanks 02A and 02B for respectively effecting vapor-deposition on one surface. Within the respective vacuum tanks 02A and 02B are respectively provided evaporation tanks 04A and 04B wherein molten metals 03A and 03B are held, hoods 07A and 07B for leading metal vapors 05A and 05B evaporated in the evaporation tanks 04A and 04B to vapor-deposition ports 06A and 06B, and wrapping rolls 08A and 08B disposed in opposition to the vapor-deposition ports 06A and 06B, so that the band 01 is adapted to be opposed to the vapor-deposition ports 06A and 06B as wrapped around the wrapping rolls 08A and 08B, respectively. It is to be noted that in FIG. 8, reference numerals 09A and 09B designate shutters for controlling the amounts of the metal vapors 05A and 05B led to the vapor-deposition ports 06A and 06B, reference numerals 010A and 010B designate atmospheric melting tanks, numerals 011A and 011B designates snorkels for feeding the molten metals 03A and 03B from the atmospheric melting tanks 010A and 010B, respectively, to the evaporation tanks 04A and 04B, numerals 012A and 012B designate heaters for heating and evaporating the molten metals 03A and 03B within the evaporation tanks 04A and 04B, and numeral 013 designate seal devices of the vacuum tanks 02A and 02B provided at the inlet and outlet ports of the band 01.
In the above-described wrapping roll type vapor deposition apparatus, the band 01 is successively carried in as wrapped around the wrapping rolls 08A and 08B within the vacuum tanks 02A and 02B, respectively, and after vapor deposition has been effected to its surface on one side within the vacuum tank 02A and to its surface on the other side within the vacuum tank 02B, it is carried out as a vapor-deposited band 01a.
In addition, a plate type vapor deposition apparatus wherein heated flat plates are used in place of the wrapping rolls 08A and 08B was also proposed (Japanese Patent Application No. 63-7010 (1988)). This apparatus is shown in FIG. 9. In this figure, reference numerals 014A and 014B designate heated flat plates. It is to be noted that since the other construction is almost similar to that of the apparatus shown in FIG. 8, members performing the same functions are given like reference numerals, and further explanation thereof will be omitted.
In this apparatus also, the band 01 is sequentially carried into the two vacuum tanks 02A and 02B, and after vapor deposition has been effected to the surface on one side within the vacuum tank 02A and to its surface on the other side within the vacuum tank 02B, it is carried out as a vapor-deposited band 01a.
In the above-described vacuum vapor deposition apparatus in the prior art, in the case of vapor-depositing, for example, zinc to the front surface and the rear surface of the band, vacuum tanks and vapor-deposition apparatuses are respectively necessitated two, and also, since the atmospheric melting furnaces or the like are also respectively provided in the respective vapor deposition apparatuses as feeding devices of zinc, there was a problem that a number of equipments was large and the cost was also high.
In addition, in the above-described apparatus shown in FIG. 8 or 9, in the case of carrying out differential thickness plating in which an amount of vapor-deposition of zinc is made different between the front surface and the rear surface of the band 01, the amounts of deposition on the front and rear surfaces can be respectively controlled by means of the shutters 09A and 09B. However, in the case where vapor deposition ports are provided on the front surface side and on the rear surface side of the band, for instance, within a single vacuum tank for the purpose of reducing the number of equipments, there is a problem that upon carrying out differential thickness plating the vapors on the front surface side and on the rear surface side would interfere and would result in irregularity in the distribution of a deposited amount.